Process for the production of valuable hydrocarbon products by the extraction of solid carbonaceous materials



Sept. 17. 1940. M HER. ETAL PROCESS FOR THE PRDDUCTION 0F VALUBLE HYDROCARBON PRODUCTS BY THE EXTRACTION OF SOLID CARBONACEOUS MATERIALS Filed July 21, 1937 Patented Sept. 17, 1940 UNITED STATES PATENT yoI-Flcs- MATERIALS Mathias Pier, Heidelberg, and Ernst Donath,

Mannheim, G

ermany, assignors to Standard- I. G. Company, Linden, N J., a corporation of Delaware Application July 21, 1937, serial No. 154,920

1n Germany July 23, 193e s claims. (ci. 19o-14) The present invention relates to a process for the treatment with hydrogenating gases, especially to the destructive hydrogenation of extraction products of solid carbonaceous materials,

tures. After the extraction, the mixture of so1.

vent and extract obtained is usually first mecham'cally freed from solid substances, for example, by filtering or centrifuging, and the solvent is then removed from the mixture by distillation. The remaining extract is a useful initial material for the production, by treatment with hydrogenating gases, of hydrocarbon oils 20 such as gasoline, Diesel oil, lubricating oil and the like, and for such destructive hydrogenation, it may be diluted with heavy or middle oil. We have ascertained that, due to the great reactivity of the extracted products, the removal of the solvent by distillation causes substantial alterations, for example, polymerizations, of the constituents of the extract, which alterations in turn cause undesirable disturbances when the extract is used, for instance as fuel oil, or preferably when it is subsequently treated with hydrogenating gases. These disturbances result in the lowering of the speed of the reaction and of the yield of the desired hydrocarbon products.'

We have found that said undesired alterations of the extracted products are avoided, with the result that the subsequent treatment with hydrogenatinggases is substantially improved, if the removal of the solvent from the mixture of exi tract and solvent by distillation is only carried 40 out-after the addition of an organic diluent, the boiling point of which is higher than that of the solvent. The addition of the diluent prior to the removal of the solvent prevents superheating of the extract during the distillation and thus allows of the' extract being obtained substantially in its original reactive state without'alterations of its quality. The remaining mixture of extract and diluent may/then be subjected to the treatment with hydrogenating gases, forv example,

destructive hydrogenation, if desired or necessary after further dilution with middle and/or heavy oil.

The extracts suitable for treatment in accordbrown coal or peat with a solvent, such as, for example, tetrahydronaphthalene or mixtures thereof with phenols, for instance with cresols, or lower fractions of a middle oil, at temperatures between 250 to 479 centigrade, preferably between 400 and 460 centigrade, advantageously in the presence of catalysts and,'if desired, under pressure and/or in the presence of limited amounts of hydrogen, and, if desired, in several stages in which increasing temperatures and/or pressures may be employed. The extraction may be carried out a's a batch process or in continuous or intermittent operation. mixture of extract and solvent is freed from solids, such as ash, by mechanical means, for example, by ltration or,centri fuging, and a suitable organic diluent of high boiling point is then added, for example, upper middle oil and/or heavy oil fractions of tar or of hydrogenatlon productsffrom another portion/of such extract or from-gsolid carbonaceous materials; Sometimes it may be desirable to add a part or a whole of the diluent prior to or during the mechanical separation of solids, or to pass diluent to the separator 1 to `wash the residue. The solvent is then distilled off and the remaining .mixture of extract and diluent may be subjected to a treatment with hydrogenating gases, such as hydrogen or gases containing or supplying sufficient free hydrogen, for example, a destructive hydrogenation, if desired, after addition' of further amounts of oils of high boiling point, in the presence of catalysts at temperatures above 250 centigrade, say above 280 centigrade, for example, at from 300 to 500 centigrade and'under a vpressure of 20, 50, 100, 200, 300, 500 or 1,000 atmospheres or more.

The f catalysts may be dispersed 'within the The resulting initial materiahor stationarily contained in the l reactionv vessel. 'Suitable catalysts are, for example, oxides and sulphides of heavy metals, such as tungstenimolybdenum, iron, chromium and the like. 'Iin or zinc, more particularly in the form of saltsv of organic acids of low molecular weight may likewise be employed'. The cata.- lysts may be activated by promoters such.as difiicultly reducible oxides of metals, for example, thorium or cerium, and be supported on carriers, for example, activated brown coal small coke,

.,alumir.v or bleaching earth.

According to the particular conditions applied vin the treatment with hydrogenating gasesv and to the nature of the initial material, gasoline, middle oil, Diesel oil, fuel oil, heavy oil, lubricating oil and/or paraiiin wax may be obtained.

y ltration.

By a suitable regulation of the course of this operation the diluent may be recovered from the reaction products in an amount corresponding to the quantity used 'for the dilution of the mixture of extract and solvent, so that the diluent may be used again in the treatment of a fresh mixture of`extract and solvent. Similarly, the solvent which has been recovered by distillation may also serve again for the extraction of a fresh portion of initial solid-carbonaceous material.

The treatment with hydrogenating gases is usually carried out as a continuous process, although batch operations or intermittent operations may be applied.

The following example and the drawing, whichv is a; diagrammatic illustration in partial sectional elevation of suitable equipment for carrying out this process and which indicates the ow of ma- Example Gas flame coal is admixed with 1.5 times its weight of a. mixture of 80 per cent of tetrahydronaphthalene and 20 per cent of cresol. The whole is heated at 400 centigrade during two and a half hours under a pressure of 100 atmospheres. 85 per cent of the organic substances contained in the coal are thusdissolved. The resulting solution is freed from solid matter, such as ash, by 1.2 parts of' heavy oil obtained from bituminous-coal and containing 15 percent by volumerof components boiling below 325 centigrade are added for each part of the solution and the mixture is subjected to' distillation at a teniperature up to 260 centigrade, measured with an instrument immersed in.the liquid; tetrahydrov naphthalene and cresol and naphthalene formed from tetrahydronaphthalene during the extraction, are distilled oil?. 'I'he remaining'mixture of extract and diluent is then subjected to destructive hydrogenation with hydrogen under a pressure ofI 600 atmospheres, at 420 centigrade, in\

asphalt and consists of an oil suitable as Diesel oil, invadmixture with a small amount of gaso-l line.

2,215,190 i If the mixture of extract and solvent be sub- Jected to distillation for the removal of tetrahydronaphthalene and cresol without the addition of heavy oil, the destructive hydrogenation must be carried'out with a lower speed in orderto obtain a sumcient conversion of the initial material, but nevertheless a larger amount of'gasecus hydrocarbons is formed, so that `the yield of liquid products is substantially lower.

We claim:

1. A process for the production of valuable hydrocarbon products from products obtained by extracting solid carbonaceous materials with organic solvents, which comprises adding an organic diluent, the boiling vpointy of which is higher than that of the solvent, to the mixture of extract and solvent, subjecting the diluted mixture to distillation, thus expelling the solvent and subiecting the remaining mixture of extract and diluent to a treatment with hydrogenating gases.

2. A process as claimed in claim 1 in which the treatment with hydrogenatin'g gases is a destructive hydrogenation which is carried out attemperatures between 300 and 500, centigradeand at a pressure above 200 atmospheres.

3. A process as claimed in claim 1 in which the treatment with hydrogenating gases is `carried out in such a manner that the amount of diluent recovered from the reaction'products corresponds to the quantity used for the dilution of the mixture of extract and solvent, and using the recovered diluent for the treatment' of a fresh mixture `oi extract andL solvent.

4. A process as claimed in claim 1 in which the.

upper fractions of a diluent.`

5. Process for the manufacture of hydrocarbon oils and gasesfrom coal, which comprises heating the coal with an organic .solvent which is capable of dissolving part of the coal, freeing the solution so obtained from the undissolved residue of the coal, adding to the solution an organic diluent ,medium which boils at a temperature higher than the boiling point of the organic solvent, then removingthe solvent in vapor form, and subjecting the extracted fraction of the coal while mixed with saidorganic diluent medium to hydrogenation in the presence of a hydrogenation a middle oil are employed' as fcatalyst at an elevated temperature adapted to hydrogenate the extracted fraction to liquid oils, and under a pressure higher than atmospheric.

ERNST DONATH. 

